import tkinter as tk

window = tk.Tk()
window.title("小A君")
window.geometry("200x200")

var = tk.StringVar()
l = tk.Label(window,bg="yellow",width=20,text="empty")
l.pack()

def print_selection():
    l.config(text="you have selected "+var.get())

r1 = tk.Radiobutton(window,text="Option A",variable=var,value="A",command=print_selection)
r1.pack()
'''单项选择'''

r2 = tk.Radiobutton(window,text="Option B",variable=var,value="B",command=print_selection)
r2.pack()

r3 = tk.Radiobutton(window,text="Option C",variable=var,value="C",command=print_selection)
r3.pack()
window.mainloop()
'''不断循环刷新'''

